The replacement of gas distribution pipe typically requires the excavation of trenches into which the pipe is laid. Alternatively, a technique known as pipe insertion provides a means for the installation of distribution pipe with reduced excavation, resources, permits and reinstatement costs. Pipe insertion is the process of inserting a smaller pipe into an existing, larger one. It currently provides a means for gas companies to cost-effectively replace large sections of main without the typical disruptive excavations. A “dead insertion” is a technique where a pipe is temporarily disconnected from the existing gas distribution network. Excavations are made at suitable access points on the existing gas main. A cut-out of an excavated section of main is created and a new polyethylene (PE) pipe is pulled or pushed into the section of existing main.
Each excavation associated with a pipeline replacement results in traffic delays, road closures and noise that disrupt the public and drive-up project costs. The high project costs may eventually be passed along to the gas customers. To minimize disruptions to service, it would be desirable to have an in situ means of connecting newly inserted PE pipe to service lines to eliminate the need to excavate over the connection point with the main at each service.